Wyndle is a cultivationspren who takes the form of a vine that didn't move but grow towards his objective. The vines hardened after a few moments of sitting, as if briefly becoming solid crystal, then they crumbled to dust.[3]
He can form a sort of face by curling vines around one another. He is invisible and inaudible to all but Lift, though the hordlings of the Dysian AimianArclo seem to be able to sense him.[4] He could make himself visible to others, though has a harder time doing so than other spren.[3]

Wyndle is a gardener who enjoys a quiet life. He is very proud of his accomplishemnts on growing chairs.[1] He seems to be quite proper and intelligent. He is a cautious and nervous spren who often worries about Lift's strange behavior.

The night when the Azish kingdom was choosing a new Prime, Lift decided to help some thieves rob the palace and Wyndle helped her. She uses him to climb, spy and use regrowth to open doors. She seems to be pulling things out, when Nale comes for her. In the process of taking her, they kill the thieve partner she had just met Gawx. Lift is able to get to him and heal him before he is gone. The Azish believe Gawx had performed a miracle and make him Prime, he "pardons" Lift and Nale has to let her go.[3]

Wyndle seemed to be happy at the Palace while they were guests of honor of the new Prime Gawx. Regardless, he followed Lift to Yeddaw, where without understanding her plans, figures out they were following Nale, who she called Darkness.[1]
Upon their arrival, Lift uses Wyndle to climb into places and spy on people. She created a diversion and later followed the guard Capitan who surely would have made a report on her. As expected Nale arrived and Wyndle finds out from Lift that his plan is to kill radiants.[8]

They trail him and surely he finds a girl who had surely bonded a spren and kills her with his shardblade. Lift tries to save her, but Wyndle explains that a shardblade kills faster making Lift's timing late to bring her back. Lift continues to follow him and keeps using Wyndle to climb and spy until they find his quarters, where Lift eats his pancakes.[9]

Wyndle helps Lift get into the Grand Indicium, where she wanted him to read everything to find "weird" events. He explained there wasn't enough time, so she went to steal some fancy clothes.[10] He took the form of a word she copied and showed to the scribes of the place who then wrote to Gawx and received his request to treat Lift with respect and do as she asked.[11]Though she was unable to find anyting useful, she does find one of Nale's allies and follows them. Wyndle himself offers to spy on them and finds out they are about to go and perform the execution.[12]

When Lift confronts Nale, she speaks the words of her next ideal and transforms Wyndle into a weapon, which was just a silvery rod, that was enough to block a strike and she uses that time to convince him that the desolation has returned.[6]

After that, they returned to Azir to prepare for what was coming next. [7] Lift became a “person of trust” to the Prince, who listened and trusted her advice. [13]

Wyndle and Lift went to Urithiru to join with Dalinar. Though the Azish left before the battle, they stayed to help. Their task from Dalinar was to take a big ruby from a Fused with similar powers to and Edgedancer. Wyndle’s task was to follow the Fused who moved faster than Lift. He did, but she got hit by the rock monster, to what Wyndle answered by asking to be summoned as a shardblade to protect her. Lift summoned him as a rod but was saved by Szeth.[5] Though Lift didn’t use Wyndle to eventually get the ruby, they did complete the task and gave the rock to Dalinar, which was key to winning the battle. [14]

Wyndle is a cultivationspren that makes his radiant part of the Order of Edgedancers. This means, he grants the Surges of Abrasion and Progression. Or how Lift would say “I can slide around, awesome, and I can make stuff grow.” [15]

It is clear that Wyndle did not chose to bond with Lift but was asked to. [3] At the beginning he is frustrated with her for not letting him educate her.

Lift at first believe that he is a caught Voidbringer and calls him that. She tends to ignore him and ask him to shut up. [1]

Since the beginning, their bond has unexpected results. Even though he doesn’t have enough presence in the Physical Realm, she was able to touch him, which was not supposed to happen even with the bond. [1]

He tried to help her evolve, to get her to say the words, as he considers that his duty. She gives him a hard time as she doesn’t listen. [16]

As their relationship evolves, Wyndle starts to understand the meaning behind her words. He understands her reference on stealing Nale´s lunch which really meant saving the person he wanted to execute. And their relationship improves greatly. [17]

There's some spren that choose on their own, while there's other spren where it's done by committee. Wyndle, Lift's spren was placed with Lift by a committee. It's a culture difference. Some are free-spirited, others more organized. [18]
Lifespren will pop up more commonly around Wyndle then they will around Sylphrena . [19]